Outcomes of Combined Posterior Tibial Tendon Tendoscopy and Medializing Calcaneal Osteotomy for Stage IA Progressive Collapsing Foot Deformity.

BACKGROUND: Posterior tibial tendon (PTT) tendoscopy and medializing calcaneal osteotomy (MCO) are among the available techniques for patients presenting with symptomatic flexible hindfoot valgus (stage IA) progressive collapsing foot deformity (PCFD). The aim of this study was to determine clinical and radiographic outcomes of combined PTT tendoscopy and MCO for patients presenting with symptomatic stage IA PCFD. METHODS: A retrospective cohort study was performed in order to determine clinical and radiographic outcomes of 30 combined PTT tendoscopies and MCO on 27 patients presenting with symptomatic stage IA PCFD, with a minimum follow-up of 24 months. Patient satisfaction was assessed at last available follow-up as very satisfied, satisfied, and unsatisfied. Clinical assessment was performed evaluating preoperative and last available follow-up visual analog scale for pain (VAS-P), Foot and Ankle Outcome Score (FAOS), and the 36-Item Short Form Health Survey (SF-36). Magnetic resonance imaging (MRI) was performed preoperatively on all patients. Standard weightbearing anteroposterior, lateral, and long axial view radiographs of the foot and ankle were taken preoperatively, immediate postoperatively, at 6 weeks, 3 months, 6 months, 1 year postoperatively, and last follow-up evaluation available for each patient. RESULTS: The mean follow-up was 38.6 (range, 26-62) months. We registered 27 very satisfied, 1 satisfied, and 2 unsatisfied patients. There was statistically significant improvement on all clinical scores (VAS-P, FAOS and SF-36), as well as on lateral talo-first metatarsal and hindfoot alignment angles. We found low-grade PTT tears in 5 patients (16.67%) in whom preoperative MRI documented PTT tenosynovitis alone. CONCLUSION: We found that combined PTT tendoscopy and MCO provide significant clinical and radiographic improvement for patients presenting with symptomatic stage IAB PCFD. PTT tendoscopy should be considered in the treatment of all surgically addressed flexible valgus feet as it detects tendon tears which are frequently missed on an MRI. LEVEL OF EVIDENCE: Level IV, retrospective case series.

[Diagnostics and Therapy of Ankle Instability]. / Sprunggelenksinstabilität.

Diagnostics and Therapy of Ankle Instability Abstract. Ankle sprains are among the most common musculoskeletal injuries and therefore often treated in the emergency department or in the general practitioner's office. In the majority of cases, the lateral ligamentous complex is affected. If treated correctly, ligamentous ankle injuries have a good prognosis and in about 80% of cases full recovery can be achieved. Risk factors for the development of chronic ankle instability are an inappropriate treatment of the ankle sprain, injury of the deltoid ligament, hyperlaxity and rearfoot deformities (e.g., cavovarus foot). Diagnostics after an ankle sprain include a medical history, focused physical examination, and appropriate imaging. Concomitant injuries such as fractures, osteochondral defects or tendon injuries should be excluded. Ankle sprains are usually treated conservatively, involving bracing or immobilization - depending on the severity of ligament damage - followed by functional rehabilitation. Patients with chronic ankle instability refractory to conservative treatment, should be considered for surgical interventions.

Patient-Specific Instrumentation vs Standard Referencing in Total Ankle Arthroplasty: A Comparison of the Radiologic Outcome.

BACKGROUND: Existing literature on the superiority of patient-specific instrumentation (PSI) in total ankle arthroplasty (TAA) over standard referencing (SR) is limited. Advantages presented include better implant alignment, shorter operating times, and increased accuracy of implant size prediction. The aim of this retrospective study was to analyze PSI in the hands of an experienced foot and ankle surgeon new to both PSI and SR for this specific implant, in regard to determining implant alignment, operative times, and radiologic short-term outcome and predicting implant size for tibial and talar components. METHODS: Twenty-four patients undergoing TAA using PSI were compared to 25 patients using SR instrumentation. Outcome measures included alignment of the tibial component (α coronal plane, γ sagittal plane), the tibiotalar tilt (ß), and the talar offset x on the sagittal view as well as the presence of radiolucent lines, operation time, and wound healing. Postoperative outcome was assessed at 6 weeks, 4 months, and 1 year postoperatively. RESULTS: Implant positioning was similar in both groups, and no advantage in regard to the operative time could be seen when comparing TAA using PSI to SR. Implant size prediction was more reliable for the tibia than for the talus. Three patients (1 from the SR group and 2 from the PSI group) showed radiolucent lines around the tibial component. Two patients (both SR group) suffered delayed wound healing, albeit not requiring any additional measures. CONCLUSION: The PSI method did not show an advantage over SR in regard to positioning of the components or the duration of the surgery. The current study suggests that no initial advantage of PSI over SR are to be expected in standard total ankle replacement. LEVEL OF EVIDENCE: Level III, retrospective study.

Difference in orientation of the talar articular facets between healthy ankle joints and ankle joints with chronic instability.

Since both the talocrural and subtalar joints can be involved in chronic ankle instability, the present study assessed the talar morphology as this bone is the key player between both joint levels. The 3D orientation and curvature of the superior and the posteroinferior facet between subjects with chronic ankle instability and healthy controls were compared. Hereto, the talus was segmented in the computed tomography images of a control group and a chronic ankle instability group, after which they were reconstructed to 3D surface models. A cylinder was fitted to the subchondral articulating surfaces. The axis of a cylinder represented the facet orientation, which was expressed by an inclination and deviation angle in a coordinate system based on the cylinder of the superior talar facet and the geometric principal axes of the subject's talus. The curvature of the surface was expressed as the radius of the cylinder. The results demonstrated no significant differences in the radius or deviation angle. However, the inclination angle of the posteroinferior talar facet was significantly more plantarly orientated (by 3.5°) in the chronic instability group (14.7 ± 3.1°) compared to the control group (11.2 ± 4.9°) (p < 0.05). In the coronal plane this corresponds to a valgus orientation of the posteroinferior talar facet relative to the talar dome. In conclusion, a more plantarly and valgus orientated posteroinferior talar facet may be associated to chronic ankle instability.

Outcomes of Posterior Arthroscopic Subtalar Arthrodesis for Medial Facet Talocalcaneal Coalition.

BACKGROUND: Medial facet talocalcaneal coalition can be a painful condition. This study aimed to determine clinical and radiographic outcomes of posterior arthroscopic subtalar arthrodesis (PASTA) for adult patients presenting with symptomatic medial facet talocalcaneal coalition and normal hindfoot alignment, with a minimal follow-up of 18 months. METHODS: Between June 2017 and July 2019, this procedure was performed on 8 feet (8 patients; mean age, 55 [42-70] years; mean BMI, 29.8 [24.4-45.0] kg/m2). Clinical assessment was performed using Visual Analog Scale for Pain (VAS-P), Foot and Ankle Outcome Score (FAOS) and the 36-Item Short-Form Health Survey (SF-36). Patient satisfaction was assessed at the last available follow-up as "very satisfied", "satisfied" or "unsatisfied". Radiographic analysis was performed using plain radiography, computed tomography (CT) scan and magnetic resonance imaging (MRI). The primary outcome was to determine both clinical and radiographic outcomes. RESULTS: The mean follow-up was 25.1 (18.2-34.2) months. The authors found statistically significant improvement on all clinical scores (VASP-P, FAOS and SF-36). They registered 6 "very satisfied" patients, 2 "satisfied" patients and no "unsatisfied" patient. Fusion of the subtalar joint was observed in all patients by 12 weeks and in 5 of them as soon as 8 weeks postoperatively (mean, 9.5 [8-12] weeks). There were no cases of delayed fusion or nonunion of the subtalar joint, superficial or deep infection, neurovascular damage, thromboembolic event, screw breakage, need for hardware removal or revision surgery. CONCLUSION: This study found that PASTA is a safe and reliable technique for adult patients presenting with symptomatic medial facet talocalcaneal coalition and normal hindfoot alignment, demonstrating and maintaining clinical improvement at an average follow-up of 2 years. LEVEL OF EVIDENCE: Level IV, case series.

[Update on total ankle arthroplasty]. / Update Sprunggelenksprothetik.

Update on total ankle arthroplasty Abstract. Ankle arthritis is a major cause of impaired quality of life and affects approximately 1 % of the world population. Treatment options in end stage arthritis include ankle arthrodesis and total ankle replacement. As ankle arthroplasty preserves motion at the ankle joint it has become a popular alternative to fusion. Due to modern implantation techniques and improved prothesis designs ankle arthroplasty has emerged as a safe and effective treatment of ankle arthritis.

Subtalar joint alignment in ankle osteoarthritis.

BACKGROUND: Although it has been proposed that in mid-stage ankle osteoarthritis, the subtalar joint can compensate for deformities above the ankle joint, the evidence is weak. We thus investigated subtalar joint alignment in different stages of ankle osteoarthritis using weightbearing computed tomography (CT) scans. METHODS: The subtalar joint of 88 patients with osteoarthritis of the ankle joint and a control group of 27 healthy volunteers were assessed. Subgroups were performed according to the ankle deformity (varus and valgus) and stage of ankle joint osteoarthritis. Subtalar joint alignment was assessed on weightbearing CT scans. RESULTS: A more valgus subtalar joint alignment was found in patients with varus ankle osteoarthritis. No significant difference of the subtalar joint alignment was evident when comparing different stages of ankle osteoarthritis. CONCLUSIONS: Varus ankles compensate in the subtalar joint for deformities above the ankle joint. Compensation does not correlate with the stage of ankle osteoarthritis.

Study on the three-dimensional orientation of the posterior facet of the subtalar joint using simulated weight-bearing CT.

The purpose of this study was to describe the normal 3D orientation and shape of the subtalar calcaneal posterior facet. This is not adequately described in current literature. In a supine position both feet of 20 healthy subjects were imaged in a simulated weight-bearing CT. A cylinder and plane were fitted to the posterior facet of the surface model. The orientation of both shapes was expressed by two angles in (1) the CT-based coordinate system with the axis of the foot aligned with the sagittal axis and (2) a coordinate system based on the geometric principal axes of the subject's calcaneus. The subtalar vertical angle was determined in the intersection in three different coronal planes of the cylinder. The cylinder's axis oriented from supero-postero-laterally to infero-antero-medially. The plane's normal directed supero-antero-medially in the CT-based coordinate system, and supero-antero-laterally in the other coordinate system. The subtalar vertical angle was significantly different (p < 0.001) between the three defined coronal planes and increased from anterior to posterior. The mean diameter of the fitted cylinder was 42.0 ± 7.7 mm and the root mean square error was 0.5 ± 0.1 mm. The posterior facet can be modelled as a segment of a cylinder with a supero-postero-lateral to infero-antero-medial orientation. The morphometry of the posterior facet in a healthy population serves as a reference in identifying abnormal subtalar joint morphology. More generally this study shows the need to include the full 3D morphology in assessing the orientation of the subtalar posterior facet. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9999:1-8, 2018.

The utility of the ankle SPECT/CT scan to predict functional and clinical outcomes in supramalleolar osteotomy patients.

Combined single-photon emission computed tomography and conventional computed tomography (SPECT/CT) is a hybrid imaging modality that shows a combination of metabolic and structural information about the ankle, including arthritis. We hypothesize that uptake in specific locations within the ankle joint can be associated with both clinical outcomes and may help predict which patients will have a successful SMO. Eighty-five pre-operative SMO patients with varus (37), valgus (41), or neutral (7) alignment of the hindfoot were assessed using SPECT/CT. The level of activation on SPECT/CT scans was measured. Pre and Post-operative functional scores were recorded. Patients with medial gutter activation had significantly worse (p < 0.05) AOFAS alignment (AOFAS-A) scores pre-operatively. Patients with varus or valgus alignment did not have any difference in VAS pain scores, but those in valgus did have worse AOFAS-P (pain) scores. Those with cystic lesions had a worse FAOS score pre-operatively. Ten patients (12.5%) had a treatment failure. Pre or post-operative alignment did not correlate to a treatment failure. The only statistically significant (p = 0.036) poor prognostic indicator was a bipolar lesion. Pre-operative SPECT/CT evaluation of an ankle before a SMO can be used to clinically correlate patient-specific factors such as pain and function in the pre and post-operative period. We caution against performing a SMO in patients with bipolar activation on a pre-operative SPECT-CT scan. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2015-2021, 2018.

The subtalar joint: A complex mechanism.

Subtalar joint anatomy is complex and can vary significantly between individuals.Movement is affected by several adjacent joints, ligaments and periarticular tendons.The subtalar joint has gained interest from foot and ankle surgeons in recent years, but its importance in hindfoot disorders is still under debate.The purpose of this article is to give a general overview of the anatomy, biomechanics and radiographic assessment of the subtalar joint.The influence of the subtalar joint on the evolution of ankle joint osteoarthritis is additionally discussed. Cite this article: EFORT Open Rev 2017;2:309-316. DOI: 10.1302/2058-5241.2.160050.

Pure Ankle Dislocation: A systematic review of the literature and estimation of incidence.

BACKGROUND: Ankle dislocation without fracture is rare. We used electronic hospital records to determine the incidence of pure ankle dislocation and performed a systematic review of the literature to investigate the occurrence, treatment and outcome of this injury to better inform treating clinicians. METHODS: A review of electronic medical records at a tertiary referral centre was conducted to estimate in incidence of pure ankle dislocation. Systematic review of the literature was undertaken according to PRISMA guidelines for the reporting of individual patient data. This identified 64 English language articles that included 18 case series, 45 case reports and 1 biomechanical cadaveric study. Data was extracted by standard form independently by 2 of the authors and descriptive statistics were used to describe results. RESULTS: The estimated incidence of pure ankle dislocation is 0.065% (13/20,000) of presentations with an ankle injury or 0.46% (23/5000) of presentations with an ankle dislocation. Systematic review of English literature identified 154 cases and demonstrated that sporting accidents (31%) and motor vehicle accidents (30%) are the most common cause. 73% (112/154) of the cases occurred in males and 50% (77/154) were open. In 46% (71/154) of patients the direction of dislocation was posteromedial. 46% of patients had nonoperative treatment; ligamentous repair was described in 26% (37 patients). The mean period of immobilisation was just over 6 weeks (range 2-16 weeks). In most patients, good functional outcomes were described. The most common long-term complaint was decreased ankle range of motion (18%) (27/154). Ankle instability was rare (2.6%) (4/154) and not influenced by acute ligament repair (P=0.98). CONCLUSION: Pure ankle dislocation is a rare injury. The literature reports that most injuries occur in sports and motor vehicle accidents. The majority of injuries treated with early reduction followed by a short period of immobilisation and functional rehabilitation have good clinical outcomes.

Supramalleolar Osteotomy for Tibial Component Malposition in Total Ankle Replacement.

BACKGROUND: Persistent pain despite a total ankle replacement is not uncommon. A main source of pain may be an insufficiently balanced ankle. An alternative to the revision of the existing arthroplasty is the use of a corrective osteotomy of the distal tibia, above the stable implant. This strictly extraarticular procedure preserves the integrity of the replaced joint. The aim of this study was to review a series of patients in whom a corrective supramalleolar osteotomy was performed to realign a varus misaligned tibial component in total ankle replacement. We hypothesized that the supramalleolar osteotomy would correct the malpositioned tibial component, resulting in pain relief and improvement of function. METHODS: Twenty-two patients (9 male, 13 female; mean age, 62.6 years; range, 44.7-80) were treated with a supramalleolar osteotomy to correct a painful ankle with a varus malpositioned tibial component. Prospectively recorded radiologic and clinical outcome data as well as complications and reoperations were analyzed. RESULTS: The tibial anterior surface angle significantly changed from 85.2 ± 2.5 degrees preoperatively to 91.4 ± 2.9 degrees postoperatively ( P < .0001), the American Orthopaedic Foot & Ankle Society hindfoot score significantly increased from 46 ± 14 to 66 ± 16 points ( P < .0001) and the patient's pain score measured with the visual analog scale significantly decreased from 5.8 ± 1.9 to 3.3 ± 2.4 ( P < .001). No statistical difference was found in the tibial lateral surface angle and the range of motion of the ankle when comparing the preoperative to the postoperative measurements. The osteotomy healed in all but 3 patients on first attempt. Fifteen patients (68%) were (very) satisfied, 4 moderately satisfied, and 3 patients were not satisfied with the result. CONCLUSION: The supramalleolar osteotomy was found to be a reliable treatment option for correcting the varus misaligned tibial component in a painful replaced ankle. However, nonunion (14%) should be mentioned as a possible complication of this surgery. Nonetheless, as a strictly extraarticular procedure, it did not compromise function of the previously replaced ankle, and it was shown to relieve pain without having to have revised a well-fixed ankle arthroplasty. LEVEL OF EVIDENCE: Level IV, case series.

Mid- to Long-term Results of Supramalleolar Osteotomy.

BACKGROUND: Good clinical and radiographic short-term results have been reported for patients who underwent realignment surgery of the hindfoot for treatment of early- and mid-stage ankle osteoarthrosis (OA). However, no mid- to long-term results have been reported. The aim of this study was to gain a better insight into the indications and contraindications for realignment surgery. METHODS: Two hundred ninety-four patients (298 ankles) underwent realignment surgery between December 1999 and June 2013. Kaplan-Meier survival analysis was performed with total ankle replacement and arthrodesis of the ankle joint as endpoints. A Cox proportional hazards model was performed to identify risk factors for failure. The mean time to follow-up was 5.0 ± 3.7 years. RESULTS: The overall 5-year survival rate was 88%. Thirty-eight patients (12.9%) underwent either secondary total ankle replacement or ankle arthrodesis (30 total ankle replacements, 8 ankle arthrodesis). Risk factors for failure following realignment surgery were age at the time of surgery and a Takakura score of 3b preoperatively. CONCLUSION: Realignment surgery of the hindfoot was an excellent treatment option for young and physically active patients with early to mid-stage ankle OA. LEVEL OF EVIDENCE: Level IV, prospective observational study.

Supramalleolar Osteotomies for the Treatment of Ankle Arthritis.

Supramalleolar osteotomy is a joint-preserving surgical treatment for patients with asymmetric valgus or varus ankle arthritis. The primary goal of the procedure is to realign the spatial relationship between the talus and tibia and thereby normalize joint loading within the ankle. Procedures to balance the soft tissues, as well as hindfoot osteotomy and arthrodesis, may also be necessary. Clinical studies of supramalleolar osteotomy demonstrate that correction of the altered biomechanics associated with asymmetric arthritis improves functional outcomes.

Orientation of the Subtalar Joint: Measurement and Reliability Using Weightbearing CT Scans.

BACKGROUND: Up to 60% of patients with an osteoarthritic ankle joint develop talar tilt with progression of the osteoarthritic process. The configuration of the subtalar joint, in particular the posterior facet, may contribute to the development of this wear pattern. Recently, the subtalar vertical angle (SVA) was used to describe the posterior facet of the subtalar joint in the frontal plane. The aim of this work was to analyze if the orientation of the subtalar joint may influence the type of asymmetric ankle osteoarthritis. METHODS: In total, 60 ankles were retrospectively analyzed including 40 osteoarthritic patients and 20 healthy controls. The osteoarthritic ankles were divided into 4 groups: varus ankle joints with (incongruent) or without (congruent) a tilted talus and valgus ankle joints with (incongruent) or without (congruent) a tilted talus. The orientation of the subtalar joint was described using the SVA. The SVA was determined for every patient using weightbearing CT scans. Additionally, the inter- and intraobserver reliability was assessed using intraclass correlation coefficients (ICCs). RESULTS: The inter- and intraobserver reliability was excellent (ICC > 0.989 and >0.975, respectively). The varus groups (incongruent and congruent) had significantly lower SVA values, that is, more varus orientation of the subtalar joint than the valgus groups (P < .05). The SVA of the control group was between the values of the varus and valgus ankles. CONCLUSION: The SVA provided a reliable and consistent method to assess the varus/valgus configuration of the posterior facet of the subtalar joint. In our cohort, varus osteoarthritis of the ankle joint occurred with varus orientation of the subtalar joint whereas in patients with valgus osteoarthritis, valgus orientation of the subtalar joint was found. Our data suggest that the subtalar joint orientation may be a risk factor for the development of ankle joint osteoarthritis. LEVEL OF EVIDENCE: Level III, retrospective case control study.

Chronic Ankle Instability (Medial and Lateral).

Ankle ligament injuries are among the most frequent reasons for emergency consultations of athletes. A majority of these can be treated conservatively; however, up to 40% develop chronic ankle instability requiring surgical reconstruction to restore functionality.

Medial approach to the subtalar joint: anatomy, indications, technique tips.

The medial approach to the subtalar joint allows good visualization of the articular surfaces. Compared with the lateral approach, advantages are found particularly in flatfoot correction, in which the single-incision technique can be used for corrective fusions of rigid flatfoot deformity. Union rates are comparable with the traditional lateral approach; however, wound healing problems occur less frequently. Avascular necrosis of the talus is a rare but serious complication, although frequency seems to be independent of the approach chosen. Clinical studies showed no increased morbidity when comparing the medial to the lateral approach.